CVE-2026-11858
Missing authorization in Quanos SCHEMA ST4 Client Update Service allows arbitrary file overwrite as SYSTEM
Description
Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service. The update service runs as NT AUTHORITY\SYSTEM and exposes a .NET Remoting interface over a named pipe without sufficient access controls or authorization. A local authenticated low-privileged user can connect to the interface and invoke privileged update methods such as Update(). This allows arbitrary file write and delete operations with SYSTEM privileges and can be used to achieve local privilege escalation.
INFO
Published Date :
June 17, 2026, 1:19 p.m.
Last Modified :
June 17, 2026, 4:21 p.m.
Remotely Exploit :
No
Source :
551230f0-3615-47bd-b7cc-93e92e730bbf
Affected Products
The following products are affected by CVE-2026-11858
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | 551230f0-3615-47bd-b7cc-93e92e730bbf | ||||
| CVSS 4.0 | HIGH | 551230f0-3615-47bd-b7cc-93e92e730bbf |
Solution
- Apply vendor patches for Quanos SCHEMA ST4.
- Implement proper access controls for the update service.
- Remove or restrict privileged methods if possible.
- Monitor for unauthorized service access attempts.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-11858.
| URL | Resource |
|---|---|
| https://r.sec-consult.com/quanos |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-11858 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-11858
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-11858 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-11858 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-11858', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-17T14:56:14.233126Z'} -
New CVE Received by 551230f0-3615-47bd-b7cc-93e92e730bbf
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Quanos Solutions GmbH', 'product': 'SCHEMA ST4', 'versions': [{'status': 'affected', 'version': 'SCHEMA ST4 on-premises, all versions'}], 'defaultStatus': 'affected'}] Added Description Quanos SCHEMA ST4 on-premises contains a local privilege escalation vulnerability in the Client Update Service. The update service runs as NT AUTHORITY\SYSTEM and exposes a .NET Remoting interface over a named pipe without sufficient access controls or authorization. A local authenticated low-privileged user can connect to the interface and invoke privileged update methods such as Update(). This allows arbitrary file write and delete operations with SYSTEM privileges and can be used to achieve local privilege escalation. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-862 Added Reference https://r.sec-consult.com/quanos